The invention relates to small molecule therapeutics, particularly tricyclic compounds such as phenanthrene diones.
Chemokines are chemotactic cytokines that belongs to a large family of chemoattractant molecules involved in the directed migration of immune cells (Schall, T. The Chemokines. In The Chemokine Handbook; Thompson, A., Ed., Academic Press: San Diego, Calif., 1994; pp419-460). The physiological role of chemokines in the immune process is to elicit mobilization of immune cells against pathogenic organisms by direct recruitment and activation.
Chemokines are small proteins that are divided into two main classes, based on the position of the first two cysteines, the Cxe2x80x94Xxe2x80x94C and Cxe2x80x94C families of chemokines (two smaller branches of this family have been described, the C and CX3C subfamilies). Chemokines and their receptors have been implicated as having important roles in a number of disease states, including Guillian-Barre Syndrome (GBS), Rheumatoid arthritis (RA), Allograft rejection, Psoriasis, Atherosclerosis, Asthma, Angiogenesis, Inflammatory Bowel Disease (IBD), Acute Respiratory Distress Syndrome (ARDS), and all other diseases known as autoimmune diseases.
In addition to their well-established role in the immune systems, recent studies strongly suggesting their involvement in the maintenance of Central Nervous System (CNS) homeostasis, in neuronal patterning during ontogeny and as potential mediators of neuroinflammation, playing an essential role in leukocyte infiltration into the brain (Mennicken, F. et. al., (1999) Trends Pharmacol. Sci. 20 (2): 73-78). Their expression is rapidly induced by various neuroinflammatory stimuli, implicating them in various neurological disorders such as trauma, stroke, and Amyotropic Lateral Sclerosis (ALS), Parkinson""s, and Alzheimer""s disease, in tumor induction and in neuroimmune disease such as multiple sclerosis (MS) or acquired immunodeficiency syndrome (AIDS). Both MS and GBS, are initiated by an autoimmune reaction involving T-lymphocytes (T-cells).
Multiple Sclerosis (MS) is a disease that primarily afflicts young adults. The diseases is often initially characterized by temporary partial paralysis, with remission of disease followed by relapses of greater severity and duration resulting ultimately in permanent disability in many cases. One of the hallmarks of MS disease is the infiltration and activation of peripheral blood leukocytes into the brain. This along with central nervous system immune cell activation may lead to active demyelination of the central nervous system.
Psoriasis, a common genetic skin disease, is a well known angiogenesis-dependent disorder that is characterized by marked dermal neovascularization. Keratinocytes isolated from psoriatic plaques demonstrate a greater production of angiogenic activity, as compared to normal keratinocytes. This aberrant phenotype is due, in part, to a combined defect in the overproduction of the angiogenic cytokine IL-8, and a deficiency in the production of the angiogenesis inhibitor, thrombospondin-1, resulting in a proangiogenic environment (Keane, M. P. and Strieter, R. M. (1999) in Mantovani A (ed): Chemokines. Chem Immunol. Basel, Karger, 72: 86-101).
In rheumatoid arthritis (RA), the unrestrained proliferation of fibroblasts and capillary blood vessels leads to the formation of prolonged and persistent granulation tissue of the pannus whose degradative enzymes contribute to profound destruction of joint spaces. In both psoriasis and rheumatoid arthritis, CXC Chemokine specifically IL-8 plays a very important role (Nickoloff, B. J. et. al., (1994) Am. J. Pathol. 144: 820-828). Finding an antagonist for these specific chemokines or Chemokine receptors can be a novel approach in the treatment of solid tumors, inflammatory diseases and chronic fibroproliferative disorders.
Atherosclerosis is a disease appearing not only at old age but also in early adulthood. Atherosclerosis is a cardiovascular disease related to the accumulation of fatty streak around arteries. These arterial fatty streaks are composed of lipid-laden macrophages (foam cells) and is the precursor of more complex and dangerous lesions. The participation of inflammatory cells in atherosclerosis is a well known process that involves numerous molecules including chemotactic cytokines (chemokines) for their entry into the vessel wall. The CC Chemokine, MCP-1 and its receptor, CCR-2, has been identified as an extremely potent and has been cloned and characterized in some detail (Charo, I. F. (1999) Mantovani A (ed): Chemokines, Chem Immunol. Basel, Karger, 72: 30-41). With regard to CCR, the available studies support an important role for MCP-1 in the development of early atherosclerosis lesions and in T-cell polarizations. The role of classic CXC Chemokine, IL-8 (KC/growth-related oncogene alpha in mice) and its receptor CXCR-2 has shown physiological significance in pathogenesis of atherosclerosis. CXCR-2 is strongly expressed on macrophages (Mphi) in atherosclerosis lesion (Boisvert, W. A. et. al., (2000) Immunol. Res. 21(2-3): 129-137).
During inflammation, neutrophils are removed from inflammatory sites by a process of programmed cell death known as apoptosis, leading to their recognition and phagocytosis by macrophages (Savill, J. S. et. al., (1989) Journal of Clinical Investigation 83:865). Any significant delay in neutrophil apoptosis can lead to excessive accumulation and damage to surrounding tissues (Hallet, M. B. and Lloyds, D., (1995) Immunology Today 16: 264). Tumor necrosis factor-alpha (TNF-xcex1) has been shown to induce extensive apoptosis in neutrophils within three hours.
This is the latest field in research to understand the cause of acute inflammatory diseases such as, inflammatory bowel diseases (IBD) and acute respiratory distress syndrome (ARDS). Finding an inhibitor which can inhance apoptosis can lead to disease cure for rheumatoid arthritis, inflammatory bowl disease, lung disease, gouty inflammation, and ARDS etc. Activated neutrophils plays a major role in the pathogenesis of acute respiratory distress syndrome, and persistence of pulmonary neutrophils is related to poor survival. Granulocyte colony stimulating factor (G-CSF) as well as IL-8 plays a role in the mechanisms of pulmonary neutrophilia in acute respiratory distress syndrome (Aggarwal, A. et. al., (2000) Eur. Respir. J. 15(5): 895-901 and Dunican, A. L. et. al., (2000) Shock 14(3):248-288, discussion page 288-289) as well as in inflammatory bowl diseases (Brannigan, A. E. et. al., (2000) Shock 13(5): 361-366).
Monocyte chemoattractant protein-1 (MCP-1) was the first CC Chemokine to be characterized biologically and has been shown to attract monocytes but not neutrophils (Baggiolini M, Dewald B, Moser B. (1994) Interleukin-8 and related chemotactic cytokines xe2x80x94CXC and CC chemokines. Adv. Immunol. 55:97-179). MCP-1 is a member of the xcex2-Chemokine family which acts through specific receptors to recruit monocytes, basophils, and T-lymphocytes to sites of inflammation.
MCP-1 has been reported to stimulate an increase in cytosolic free calcium and the respiratory burst in monocytes, and to activate monocyte-mediated tumoristatic activity, as well as to induce tumoricidal activity (see for example Rollins, Mol. and Cell. Biol. 11:3125-31(1991) and Walter, (1991) Int. J. Cancer 49:431-35. MCP-1 has been implicated in mediating monocytic infiltration of tissues in inflammatory processes such as rheumatoid arthritis and alveolitis (see for example Koch, (1992) J. Clin. Invest. 90:772-79 and Jones, (1992) J. Immunol. 149:2147-54). Existing data suggest that MCP-1 may play an important role in the recruitment of monocyte-macrophages to atherosclerotic lesions (see for example, Nelken, (1991) J. Clin. Invest 88:1121-27, Yla-Herttuala, (1991) Proc. Nat""l. Acad. Sci. USA 88:5252-56 and Cushing, (1990) Proc. Natl. Acad. Sci. USA 87:5134-38). In animal models, MCP-1 has been shown to be expressed in the brain after focal ischemia (Kim, J. S., (1995) J. Neuroimmunol. 56, 127-34; Wang, X., et al. (1995) Stroke 26, 661-5), and during experimental autoimmune encephalomyelitis (Hulkower, K., et al. (1993) J. Immunol. 150, 2525-33; Ransohoff, R. M., et al. (1993) 7, 592-600). MCP-1 is therefore implicated as an important mediator of the disease process for which these systems serve as animal models, such as atherosclerosis and multiple sclerosis.
In psoriatic lesions, it has been suggested that MCP-1 regulates the interaction between proliferating keratinocytes and dermal macrophages, and that MCP-1 may also serve to recruit mononuclear cells (Schroder, J. M. (1992) Arch. Dermatol. Res 284 Suppl 1, S22-6; Gillitzer, R., et al (1993) J. Invest. Dermatol. 101, 127-31). It has recently been shown that MCP-1 acts on CD4+ and CD8+ T lymphocytes as a chemoattractant both in vitro and in vivo, in addition to its effect on monocytes (Loetscher, P., et al. (1994) FASEB J. 8, 1055-60; Carr, M. W., et al. (1994) Proc. Natl. Acad. Sci. USA 91, 3652-6; Taub, D. D., et al. (1995) J Clin Invest. 95(3):1370-6). Natural killer cells that have been stimulated by interleukin-2, are also subject to chemotaxis by MCP-1 (Maghazachi, A A., et al. (1994) J. Immunol. 153, 4969-77; Allaven, P., et al. (1994) Eur. J. Immunol. 24, 3233-6. The existing data therefore indicates that MCP-1 plays a role in the recruitment of effector cells into a wide range of inflammatory lesions.
In addition to the effects on monocytes and T lymphocytes, MCP-1 has been shown to be a moderate chemoattractant and potent activator of allergy mediator release, such as histamine and leukotrienes, from basophils (Kuna, P., et al. (1992) J. Exp. Med. 175, 489-93; Bischoff, S. C., et al. (1992) J. Exp. Med. 175, 1271-7; Bischoff, S. C., et al. (1993) Eur. J. Immunol. 23, 761-7).
The MCP-1 receptor is reportedly expressed in two forms that differ because of alternative splicing of the mRNA in the region encoding the carboxy-terminal of the protein. The alternative forms have been designated MCP-1-RA and MCP-1-RB (Charo, I. F., et al. (1994) Proc. Natl. Acad. Sci. USA, 91, 2752-56). These receptors are together designated herein as CCR-2, and appear to be expressed in monocytes, myeloid precursor cells and activated T lymphocytes (Myers, S. J., et al, 1995. J. Biol. Chem., 270, 5786-5792, Qin, S. et al. 1996. Eur. J. Immunol. 26, 640-647). CCR-2 has been cloned (see U.S. Pat. No. 6,132,987 issued to Charo et al. Oct. 17, 2000), disclosing a sequence that indicates that CCR-2 belongs to a family of seven transmembrane-type chemokine receptors.
U.S. Pat. No. 6,084,075 issued to Lind et al. on Jul. 4, 2000 discloses agonist and antagonist antibodies to CCR-2, and teaches that such antibodies may be useful for treating diseases such as inflammation, rheumatoid arthritis, mononuclear-phagocyte dependent lung injury, idiopathic pulmonary fibrosis, sarcoidosis, focal ischemia, autoimmune encephalomyelitis, stroke, multiple sclerosis, psoriatic lesions, and chronic transplant rejection.
Interleukin-8 (IL-8) belongs to the CXC chemokine family. Many different names have been applied to IL-8, such as neutrophil attractant/activation protein-one (NAP-1), monocyte derived neutrophil chemotactic factor (MDNCF), neutrophil activating factor (NAF), and T-cell lymphocyte chemotactic factor. IL-8 is a chemoattractant for neutrophils, basophils, and a subset of T-cells. It is produced by a majority of nucleated cells including macrophages, fibroblasts, endothelial and epithelial cells exposed to TNF, IL-1xcex1, IL-1xcex2 or LPS, and by neutrophils themselves when exposed to LPS or chemotactic factors such as fMLP (Baggiolini M., et. al., (1989) Journal of Clinical Investigation 84: 1045; Schroder, J. et. al., (1987) Journal of Immunology 139: 3474; ibid, (1990) Journal of Immunololgy 144: 2223; Strieter et. al., (1989) Science 243: 1467; ibid, (1989) Journal of Biological Chemistry 264: 10621; Cassatella et. al., (1992) Journal of Immunology 148: 3216).
Two receptors for IL-8, CXCR-1 (IL-8RA/R1) and CXCR-2 (IL-8RB/R2), are expressed on neutrophils (Baggiolini, M. et. al., (1997) Annual Review of Immunology 15: 675-705). They share 77% identical amino acids, and their genes are colocalized on chromosome 2q35 (Holmes, W. E. et. al., (1991) Science 253:1278-1280 and Murphy, P. M. and Tiffany, H. L., (1991) Science 253: 1280-1283). One receptor, CXCR-2, has high affinity for IL-8 and all other CXC chemokines that attract neutrophils (e.g. the GRO proteins, NAP-2, etc.), while the other, CXCR-1, has high affinity for IL-8 only (Baggiolini, M. et. al., (1994) Adv. Immunol. 55: 97-179). IL-8 receptors are also found on monocytes, basophils, and eosinophils, but the responses of these cells to IL-8 are much weaker than those of neutrophils (Baggiolini, M. et. al., (1994) Adv. Immunol. 55: 97-179).
IL-8 exerts its biological activities by binding to specific cell surface receptors, CXCR-1, and CXCR-2. Both receptors binds IL-8 with high affinity but they have different affinities for MGSA/Groalpha and NAP-2. It has been shown that the expression of epidermal CXCR-2 is increased in psoriasis, suggesting that activation of keratinocytes (KC) mediated by CXCR-2 contributes to the characteristic epidermal changes observed in psoriasis (Kondo, S. et. al., (2000) J. Cell Physiol. 183(3): 366-370).
IL-8 (ELR+) was the first CXC Chemokine to be found to induce angiogenesis (Keane, M. P. and Strieter, R. M., The Role of CXC Chemokines in the Regulation of Angiogenesis, Mantovani, A. (ed.): (1999) Chemokines, Chem. Immunol. Basel, Karger 27: 86-101). IL-8 was shown to mediate both in-vitro endothelial cell chemotactic and proliferative activity, as well as in-vivo angiogenesis in the absence of preceding inflammation using bioasays of angiogenesis (Strieter, R. M. et. al., (1992) American Journal of Pathology 141: 1279-1284). In continuation to this, IL-8 been found to be significantly elevated in non-small cell lung cancer (NSCLC) (Smith, D. R. et. al., (1994) Journal of Experimental Medicine 179: 1409-1415). In Addition, IL-8 was determined to be a major angiogenic factor contributing to overall tumor-derived angiogenic activity in NSCLC (Arenberg, D. A. et. al., (1995) Journal of Investigation Medicine 43: (suppl 3) 479A).
In various aspects, the invention provides methods for the use of chemokine-receptor-binding compounds (which may be chemokine receptor ligands such as chemokine receptor agonists or antagonists), or salts thereof, in treating chemokine or chemokine receptor mediated diseases, such as MCP-1 or IL-8 mediated diseases, or diseases mediated by chemokine receptors CXCR-1, CXCR-2, CCR-2 and CCR-4.
In some embodiments, the invention relates to methods of using a tricyclic compound of formula (I), (II), (III) or (IV), or a pharmaceutically acceptable salt thereof, to formulate a medicament for the treatment of a chemokine mediated disease state, or to treat such a disease: 
In the foregoing formulae: xe2x80x9caxe2x80x9d may be 0 or an integer from 1 to 4 (with a maximum of 3 in the case of formula IV); xe2x80x9cbxe2x80x9d may be 0 or an integer from 1 to 4 (with a maximum of 3 in the case of formula IV); xe2x80x9cXxe2x80x9d may be C or N; xe2x80x9cYxe2x80x9d may be C or N; and, xe2x80x9cZxe2x80x9d may be C or N. Where xe2x80x9caxe2x80x9d or xe2x80x9cbxe2x80x9d are greater than 1, the relevant substituents need not be the same, so that if a=2 in the substituent (R1)2, the two R1 groups may be the same or different.
In some embodiments, ring A may be aromatic and may be heterocyclic with one or more heteroatoms selected from the group consisting of oxygen and nitrogen. Ring C may be aromatic and may be heterocyclic with one or more heteroatoms selected from the group consisting of oxygen and nitrogen. Ring B may be aromatic or non-aromatic and may be heterocyclic with one or more heteroatoms selected from the group consisting of oxygen and nitrogen.
In alternative embodiments, R1 and R2 at each occurance may independently be selected from substituents having a selected number of atoms, such as 100, 50, 25, 20, 15, 10, 5 or fewer atoms, wherein the substituent may be selected from the group consisting of: H; substituted or unsubstitued alkyls, such as, C1-10 alkyls, C1-6 alkyls; substituted or unsubstitued cycloalkyls, such as C3-6 cycloalkyls; substituted or unsubstitued alkenyls, such as C2-6 alkenyls; substituted or unsubstitued alkynyls, such as C2-6 alkynyls; substituted or unsubstitued aryls; substituted or unsubstitued heterocycles; hydroxyls; aminos; nitros; thiols; primary, secondary or tertiary amines; imines; amides; phosphonates; phosphines; carbonyls; carboxyls; silyls; ethers; thioethers; sulfonyls; sulfonates; selenoethers; ketones; aldehydes; esters; xe2x80x94CF3; xe2x80x94CN; and combinations thereof.
In alternative embodiments, R3, R4 and R5 at each occurance may independently be selected from substituents having a selected number of atoms, such as 100, 50, 25, 20, 15, 10, 5 or fewer atoms, wherein the substituent may be selected from the group consisting of: H; substituted or unsubstitued alkyls, such as C1-5 alkyls; substituted or unsubstitued cycloalkyls, such as C3-5 cycloalkyls; substituted or unsubstitued alkenyls, such as C2-5 alkenyls; substituted or unsubstitued alkynyls, such as C2-6 alkynyls; substituted or unsubstitued aryls; substituted or unsubstitued heterocycles; hydroxyls; aminos; nitros; thiols; primary, secondary or tertiary amines; imines; amides; phosphonates; phosphines; carbonyls; carboxyls; silyls; ethers; thioethers; sulfonyls; sulfonates; selenoethers; ketones; aldehydes; esters; xe2x80x94CF3; xe2x80x94CN; and combinations thereof.
In some embodiments, there may be at least one hydrogen bond acceptor at or attached to position X, Y, R3, R4 or R5, which may for example be attached directly to such a position (i.e. attached at the selected position by one chemical bond with no intervening atoms).
In some embodiments, the chemokine may be selected from the group consisting of: IL-8, MCP-1, and chemokines that bind to a chemokine receptor in a mammal selected from the group such as CXCR-1, CXCR-2, CCR-2 and CCR-4.
In various embodiments, the invention provides for the use of compounds of the invention in the treatment of diseases selected from the group consisting of inflammation, acute inflammation, chronic inflammation, atherosclerosis, psoriasis, gout, acute pseudogout, acute gouty arthritis, arthritis, rheumatoid arthritis, allograft rejection, chronic transplant rejection, asthma, stroke, mononuclear-phagocyte dependent lung injury, idiopathic pulmonary fibrosis, sarcoidosis, focal ischemia, autoimmune encephalomyelitis, multiple sclerosis, atopic dermatitis, asthma, chronic obstructive pulmonary disease, adult respiratory distress syndrome, inflammatory bowel disease. Crohn""s disease, ulcerative colitis, septic shock, endotoxic shock, gram negative sepsis, toxic shock syndrome, cardiac and renal reperfusion injury, glomerulonephritis, thrombosis, graft vs. host reaction, alzheimers disease, allograft rejections, malaria, restinosis, and angiogenesis.
Methods of the invention may comprise administering an effective amount of a tricyclic compound of the invention, such as phenanthrene-9,10-dione, or a pharmaceutically acceptable salt thereof, to a patient in need of such treatment. The invention also provides pharmaceutical compositions for use in such therapy, optionally comprising a pharmaceutically acceptable excipient, diluent or carrier.
In another aspect, the invention provides methods of inhibiting the binding of a chemokine, such as MCP-1 or IL-8, to its receptors, such as CXCR-1, CXCR-2, CCR-2 and CCR-4. Such methods may be used in vivo, such as in a mammal, or in vitro. Such methods may comprise administering to a mammal an effective amount of a compound of the invention, such as phenanthrene-9,10-dione.